Electric fluid heater



Sept. 2 1924.

1,507,544 L. B. CHEATHAM ELECTRIC FLUID HEATER Filed March 22 1924' 2 Sheets-Sheet 2 L ovmp B. 0/0: T/mm,

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A5 T 2/ 22 /4 l Patented Sept. 2, 1924.

- UNITED STATES I 1,501,544 PATENT oFI-"lca.

LOVERD B. CHEATHAH, OF'A'ILANTA, GEORGIA, ASSIGNOB TO 1?. AND S. ELECTRIC HEATING COMPANY, OI WILMINGTON, DELAWARE, A. CORPORATION OF DELA- WARE.

ELECTRIC FLUID HEATER.

Application filed March 28,

To all whom it may concern:

Be it known that I, Lovnnn B. CHEATHAM, a citizen of the United States, residing at Atlanta, in the county of Fulton and State of Georgia, have invented certain new and useful Improvements in Electric Fluid Heaters, of which the following is a specification.

My invention relates to electrical water heaters.

An important object of m invention is to provide a device of the a ove mentioned character, having the maximum efliciency in heating the water, passing into or through the same.-

A further object of the invention is to provide means whereby the maximum direct contact area between the resistance element and water is afforded, at the same time permitting of the free and rapid circulation of the water.

A further object of the invention is to provide a casing through which the water is circulated of a relatively small cubic capacity, with a resistance ement of a relatively large contact area, and so arranging the parts that the ci'rculationof the water is not unduly retarded.

A further object of the invention is to provide means whereby a relativel long continuous resistance element may e employed, and will be self-adjustable throughout its entire length, to properly compensate for expansion and contraction, without liability of local distortment, which might cause the resistance elementto contact with the casing of the heater.

A further object of the invention is to provide means whereby the life of the resistance element is prolonged to the maximum, b movably supporting a. portion thereo whereby excessive local expansion or contraction is eliminated.

A further object of the invention is to provide a device of the above mentioned character, formed of few and simple parts, which may be readily standardized, whereby the device ma be made cheaply.

A further 0' ject of theinvention is to provide means for heat insulating the device, without materially increasing the cost of the same.

Other objects and advantages of the invent'ion will be apparent during the course of the following description.

1924. Serial 1T0. 701,207.

In the accompanying drawings formin a part of this specification, and in which like numerals are employed to designate like parts throughout the same,

Figure l is a side elevation of the heater, showing the same connected with a hot watar-tank,

Figure 2 is a side elevation of the heater, parts broken away, I

Figure 2" is a detail section taken on line 2 2 of Figure 2,

Figure 3 is a central vertical longitudinal section through the heater,

Figure 4 is a. vertical section taken on line 44 of Figure 3,

Figure 5 is a horizontal section taken on line 5-5 of Figure 3,

Figure 6 is a vertical section taken on line 66 of Figure 5.

In the drawings, wherein for the purpose of illustration is shown a preferred embodiment .of my invention, the numeral 10 designates the tubular body portion of the casing, which may be formed of malleable iron or any other suitable material. This tubular body portion has its upper end screw threaded for engagement within the screw threaded end of a reducing cap or socket 11, preferably formed of. malleable iron. This cap or socket tapers upwardly. ThlS reducing cap'or socket is provided with a reduced screw threaded nipple 12, as shown. The lower end of the tubular body portion is screw threaded for enga ement within the upper screw threadeden of a T-couplmg 13, also preferably formed of malleableuon. The lower end 14: of this T-coupling 1s 1nternally screw threaded for receiving a screw threaded plug 14, also preferably formed of malleable 1101'1. The plug is preferably tapered for affording a tight fit. The T- coupling-13 is provided upon one side thereof with an internally threaded mpple 15, as shown. I

The lug 14 is provided with a screw threade opening 16, drilled through its upper face, and receiving the lower screw threaded endof a supporting element or rting tially horizontal portion 18, which extends diametrically of the tubular body portion 10,-inwardly, from the rod 17. The rod 17 is spaced a slight distance from the inner wall .of the tubular body portion 10, as shown. The plug 14 is provided with a pair of vertical openings 19, formed therein, and these openings have their centers arranged upon a diameter of the plug which is at a rlght angle to the diameter of the plug disposed in the vertical plane of the horizontal extension or portion 18. The openings 19 are preferab y equidistantly spaced from the center of the plug, and these openings are also equidistantly spaced from the rod 17 and are disposed at an angle of 90 with relation to this rod. The openings are spaced a considerable distance from the inner wallof the tubular body portion 10. In the construction of the device, I preferablyemploy hard white vulcanized bone fibre sleeves 20, which are first preferably dipped into an electrical cement compound, which is insulating and acid resistant, and will dry when exposed fora suitable length of time to the atmosphere. 'While this cement is still wet, the sleeves 20 are introduced into the openings 19, and have a close fit therein. I then pass binding elements or bolts 21, preferably formed of brass or other suitable material through the coated interior of the sleeves 20, arranging a hard vulcanized white bone fibre washer 22 beneath the head of each bolt and a similar washer 23 at the lower end of the same. When the cement dries, an absolutely water tight joint is efi'ected.

The numeral 24 designates a resistance element, in the form of a continuous coil. This resistance element is folded or doubled upon itself, between its ends, and ispassed about an insulating grooved spool 25, which is rotatable upon the horizontal extension;

lower ends with nuts 28, with brass washers 29 preferably arranged between the upper nuts28 and the fibre washer 23. Termlnals 30 are clamped between the nuts 28 and these terminals carry the wires 31, as is obvious.

The resistance element or coil 24 is formed of any suitable metal such as nichrome .reslstance wire, or any other suitable metal having a high resistance and which will not corro e when directly contacting with'the water. I have found that satisfactory results may be obtained by using v a wire hav- {Ilia diameter of .036 of an inch, such. wire be g 17 feet, 6 inches long, and wound upon a mandrel of an inch in diameter.

An important feature of the invention is the arrangement of the turns of the resistance coil, which turns are distended or disposed a substantial distance apart,'so that the Watermay freely circulate between the turns, into and out of the resistance coil, thereby effecting a most intimate contact between the water and the coil, without unduly retarding the free travel of the water. As before stated, the insulating spo0l'25 is rotatable, and this is an important feature of the invention. Due to the considerable length of the resistance coil, any decided change in temperature at" any particular portion of the same, will of course cause the coil to contract or expand, and if the coil were not self-adjusting throughout its entire length, such coil would be subjected to excessive local strains or distortment whereby it might be injured, or brought into con-' tact with the casing. Since the s 001 is rotatable, any considerable contraction or expansion of the coil, at any local point, may effect the longitudinal movement of the coil throughout its entire length, such coil traveling upon the rotatable insulator 25.

Particular attention is called to the fact that the upper portion 32 of the coil is arranged generally radially at the upper end of the tubular body portion 10, and extends across the contracted nipple 12. Since the upper portion 32 is arranged around the circular spool, its turns, at the upper portion thereof which are particularly active at this point, are further distended, and this permits of the further free travel of the water, which passing upwardly through the tubular body portion 10, deflects inwardly from all sides, over and throu h these turns, as it is guided by the tapered cap or socket 11, to the contracted nipple 12. This water must be free to move rapidly at this point, for it is at the maximum temperature, and is in a sense superheated by t e upper portion 32 of the resistance coil. 1 is rapid travel of the water at this point is effective in drawing in cold water at the lower end of the tubular body portion 10.

I provi e a jacket surrounding the casing, producing a dead air heat insulating space, and this jacket embodies an upper tubular jacket section 33, having a tapered top 34, to

receive the socket or cap 11 and provided with a collar 35. At its lower end, the jacket section is slotted, at 36, for the passage of the nipple 15, the curved base 37 of the slot snugly engaging the side of the nipple. The 1113813101 bore of the jacket section 33 is of within the upper end of a lower jacket section 40, and this lower jacket section has its upper end slotted, shown. at $1, the base r 1,507,544 a B 42 of this slot snugly engagin the side of thenipple 15. It is thus seen t at the overlapping portions of the jacket sections completely enclose the hi ple, forming a substantially air tight joint therewith. At its lower end, the jacket section has a sleeve 43 for receiving'the cable 44, containing the wires 31.

The numeral 45 designates a curved name plate, which is drilled with holes 46, which oles are also extended through the overlapping portions of the jacket sections 33 and 40 and into the flange 39. Screws 47 pass through these drilled holes and have screw threaded engagement within the inner portions of these holes formed in the flange These screws thus serve to hold the name plate in place and to connect the jacket sections and anchor the same to the flange of the T-coupling.

As clearl 1 lustrated in Figure 1, a cold water supp y pipe 48, is attached within the nipple 15 and leads to the bottom of a hot water tank 49, receiving cold water through a pipe 50, as is customary. A hot water discharge pipe 51 leads into the nipple 12 and passes through the collar 35 and is connected with a discharge pipe 36 leading into the top of the tank 49, and also to the spi ot.

n the use of the heater, the water passes into the lower end of the casing and ascends therem, in direct contact with the doubled resistance coil extending longitudinally within the casing. The water passes freely between the turns of the resistance coil into and out of the same, during this u ward travel. When the water approaches t .e upper end of the resistance coil, the cap or socket 11, together with the insulating spool 25, causes the water to converge inwardly toward the horizontal portion 32 of the resistance coil, prior to its final discharge through the contracted nipple 12. I have found that the device operates with the maximum efli ciency, the water receiving the maximum heat and seeing rapidly through the device.

It is to un erstood that the form of my invention herewith shown and described is to be taken as a preferred embodiment of the same, and'that various changes in the shape,

size, and arrangement of parts may be resorted to, without departing from the spirit of my invention, or the scope of the subjoined claims.

Having thus described my invention, what I claim is:

1. An electric heater of the character described, com rising a casing, a rotatable insulating s 00 mounted within the casin near one en thereof, a resistance coil folded about the rotatable s 001 for providin longitudinal portions of t e resistance coi which extend within the casing throu hout the major portion of the length 0 said casing without having contact with other parts whereby such lon 'tudinal portions are free to adjust themse ves due to expansion or contraction, terminals connected with the ends of said lon itudinal ortions of the resistance coil, an inlet an outlet means for the casin 2. An electric fluid heater of the character described, comprising a casing provided near one end with an inlet and near its opposite end with an outlet, an insulating spool within the casing near the outlet, means arranged near the center of the spool for pivotally supporting the same, a resistance coil folded upon itself about the spool and extending throughout substantially the major portion of the length of the casing, terminals arran ed near the inlet of the casing and connected with the ends of the resistance coil, and means for attaching wires to the terminals.

3. An electric fluid heater of the charac- .and terminals arranged near the op osite end of the casing and connected-wit the ends of the resistance coil.

4. An electric fluid heater of the character described, comprising a casing, a cap secured to the upper end of the casing and tapering upwar y and having a re uced outlet, said casing having an inlet near its lower end, an insulating spool mounted within the u per portion of the casing near. and spaced rom the tapered cap, a. resistance coil folded about the spool between its ends providing a generally transverse portion arranged near the tapered cap and having its turns further opened b the spool, and longitudinal portions exten i gthrough the major portion of the length 0 the casing, and terminals arranged near the lower end of the casing and attached to the ends of the resistance coil.

5. An electric fluid heater of the character described com rising a casing provided near its upper end with an outlet and near its lower end with an inlet, a plug closing the lower end of the casing, a rod attached to the plug and extending upwardly within the casing and terminatin near the upper end of the same, said rod liaving its upper end provided with a transverse extension, 9. s 001 rotatable upon the rod, a resistance coi folded upon itself about the spool and extending downwardly therebelow, and terminals carried by the plug and attached to the ends of the resistance coil.

6; An electric fluid heater of the character described com rising, a tubular body ortion, a T-coup ing mounted upon the ower end of the tubular body portion, a lug mounted within the lower end of the coupling, a cap mounted upon the upper end 0 the tubular body portlon, a rod carried by the plug, and having a transverse portion, a spool pivotally supported by the transverse portion, a resistance coil extending about the spool, and terminals carried bythe plug and connected with the ends of the coil.

7. Anelectric fluid heater of the character described comprising, acasing having an outlet near its upper end and an inlet near its lower end, an insulating s 001 supported within the u er portion 0 the casmg, a resistance coiFlient about the spool and extending below it, terminals secured to the lower end of the casing and attached. to the ends of the coil, a jacket surrounding the casing, said jacket embodying upper and lower jacket sections having their ends tele scoping, a name late arranged over the telescoping ends 0? the jacket sections, and screws passing through the name plate and said to escopmg ends and engaging said casing.

In testimony whereof I aflix my signature.

LOVERD B. CHEAT. 

